updated 12:40 pm EST, Wed March 7, 2012

Nokia talks about the history of 41MP sensor

Nokia's 808 PureView smartphone, with its industry-beating 41-megapixel sensor, was more than five years in the making at the company, and the company's Damian Dinning now revealed the project was inspired by satellite imaging tech. Nokia has experimented with folding optics for zoom, but found the solution to be slow and noisy, before realizing images taken by satellites use large resolution sensors and then crop the image and zoom in a specific part of the image.

On the PureView, the zoom would focus on one part of the image and upscale and interpolate it to simulate the effect of an optical zoom. This would also result in a smaller physical size. Eventually, the team decided to add enough pixels to not have to upscale the image at all. Doing so would have the benefits of great low-light and optical performance while retaining a low f-stop number, or a wide aperture. File sizes would remain small thanks to the lack of noise and the amount of detail in the image would be generous thanks to pixel oversampling.

The method also allowed for a reported instant and silent zooming. Nokia worked with Carl Zeiss for optics, materials, and manufacturing technologies to integrate the sensor into the camera. The wish to support both 4:3 and 16:9 aspect ratios resulted in a 13:9 sensor module that's being used in the N9, Lumia 800, and Lumia 900.

The company considered nearly 40 design proposals, but found compromises had to be made. Nokia kept refining the process until it believed it struck the right balance.